Preservation of blood flow in both the afferent and efferent cerebral arteries from the cerebral aneurysm is crucial to obtain satisfactory surgical results in the treatment of patients with unruptured cerebral aneurysms. However, we sometimes encounter troubles regarding occlusion of efferent cerebral arteries including perforating arteries. Such troubles occur when the aneurysm neck is broad, and when wall of aneurysm and neighboring arteries is thick and arteriosclerotic.
Dome clipping sufficiently away from aneurysmal neck should be performed in such cases. Separation of efferent artery from adhesion to the dome of aneurysm may injure the arterial wall. Various functional and morphological monitoring systems (Doppler ultrasound, Transit flowmeter, Intraoperative digital subtraction angiography, motor evoked potential, somatosensory evoked potential, arterial pressure of the middle cerebral artery, among others) are helpful to detect ischemia of the efferent artery's territory. Although bypass surgery is also helpful in efferent artery occlusion, prophylactic bypass may result in better surgical result than bypass necessarily made after occlusion of the efferent artery.

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Intraoperative aneurysmal rupture at the neck may result in a disastrous postoperative course. We report a case of giant IC-PC unruptured aneurysm successfully treated by an unreported method.
A 67-years-old male was admitted to our department because of abnormal behavior. CT scan and MR image demonstrated a mass lesion compressing the right cerebral peduncle measuring 4.5 cm in maximal size. A cerebral angiogram revealed an IC-PC aneurysm on the right side. Therefore, we diagnosed a subtotally thrombosed giant IC-PC aneurysm. At surgery, the aneurysm had a surprisingly narrow neck and looked clippable. Massive bleeding occurred at the neck during application of an angled clip.
Following temporary clipping of the internal carotid artery, opening of the aneurysm fundus near the neck was followed by removal of some thrombus. Application of an angled fenestrated clip at the lacerated neck with one blade inserted into the cavity of the aneurysm resulted in no bleeding without stenosis of the internal carotid artery.

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Neck clipping of large internal carotid-posterior communicating artery (IC-PC) aneurysms is generally difficult, especially when the anterior choroidal artery adheres to the aneurysm.
We report 2 cases with premature rupture during the dissection of the anterior choroidal artery adhering to aneurysmal dome. The rupture point was not from the dissecting area, but from the medial wall of the aneurysmal dome, which also adhered to optic nerve. The traction force seemed to be the cause of tearing of the medial aneurismal wall. One patient successfully underwent clipping with temporary occlusion of the internal carotid artery, and another developed mild hemiparesis due to the cerebral infarction.
Large IC-PC aneurysms sometimes adhere to the optic nerve located to the medial side of the aneurysm, because the dome projects medially and the internal carotid artery runs medially, too.
To avoid the premature rupture, it is essential to check whether the dome wall adheres to the optic nerve before dissecting the anterior choroidal artery from the dome of aneurysm.

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To elucidate actual clinical features of patients at the poorest grade with subarachnoid hemorrhage (SAH), we studied the relation of intracranial and systemic insults. We studied 524 severely ill cases admitted within 72 hours after the onset of SAH with a Glasgow Coma Scale score (GCS) of 8 to 3 and compared them with patients with a GCS of 9 or more (907 cases) as a less ill group.
As an outcome of GCS 6 is nearly the same as that of GCS 7 and significantly different from that of GCS 5, the poorest case with SAH is to be defined as those with GCS 5 or less, and a case with GCS 6 should not be regarded as Grade 5 although the WFNS grading classifies it as Grade 5. Among cases in Grade 5, some with GCS 3 on admission showed remarkable recovery, suggesting that score 3 by GCS includes improving case though it looks as GCS 3 at present. However, cases at GCS 3 who underwent resuscitation (RES) for complete cardio-pulmonary arrest all died, while some of those receiving RES for apnea without complete cardiac arrest survived.
Assuming the value obtained from a simple formula [blood sugar level (mg/dl) / serum potassium concentration (mEq/L)] as stress index (SI), SI correlates well with serum catecholamine level at acute stage. This means that we can expect the extent of sympathetic tonus in acute SAH by SI, an easily and quickly calculable index. Cases with SI over 40 are seriously ill both neurologically and as to systemic complications (COMP) produced by a so-called sympathetic storm. Further deterioration with an SI over 50 is not predominantly brought about by pure SAH, but by additional hemorrhagic damage to the brain such as intracerebral hematoma or massive intraventricular hemorrhage. The severely ill group (GCS8-3) exhibited an extremely high mean SI of around 60 with or without COMP, while in the less ill group (GCS≥9) those with COMP showed a significantly higher mean SI (59) than those without (43).
If the patient's neurological condition is not serious but the patient shows an SI over 60, one should pay much attention to possible cardio-pulmonary complications such as cardiac arrhythmia, heart failure or pulmonary edema.

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Our prior studies revealed that favorable outcome occurred in 54% of WFNS Grade IV and 14% of Grade V patients with subarachnoid hemorrhage (SAH). To predict the outcome in patients with severe SAH, we assessed the outcome of the 192 poor-grade patients admitted to Asahikawa Red-Cross Hospital who suffered aneurysmal subarachnoid hemorrhage in the period of 1994 to 2001. Preoperative GCS with 3 and 6 presented approximately 20% of favorable outcome. None of the patients with preoperative GCS 4 or 5 presented favorable outcome.
Seventy-nine patients were rated as SD (severely disabled) in GOS (Glasgow outcome scale). Three of 79 patients were rated SD because of focal sigh, such as aphasia or hemiparesis. The remaining cases revealed variable degrees of post SAH dementia. Using multivariate analysis, we found that the age (p<0.001) and postoperative GCS (p<0.01) correlated with the outcome in SD patients.
We conclude that aggressive management can benefit patients with GCS 3 or 6 even in Grade V. The outcome of the Grade V can be rated as “acceptable” in 28% when we include SD patients with acceptable deficit. In elderly patients 75 years old and older, our preliminary data suggest preoperative GCS with 8 or better may be the borderline to expect favorable outcome.

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We report 2 cases of stent-in-stenting for the plaque protrusion after stent deployment.
In 1 case, a 69-year-old male presented right hemispheric TIA. He had received radiation therapy for middle laryngeal cancer 10 years previously. Diagnostic cerebral angiography demonstrated bilateral severe cervical carotid artery stenosis. The patient was treated with bilateral carotid artery stenting (CAS). After his left CAS, angiography showed satisfactory results, but intravascular ultrasound (IVUS) imaging revealed a plaque protrusion through the struts of the stent. Six days after the procedure, protruded plaque grew bigger and moved rapidly. An additional stent was deployed in the first stent to seal it. The patient's clinical course was uneventful.
In the second case, a 58-year-old male with unstable angina had multiple major cerebral artery stenoses (bilateral carotid arteries, left subclavian artery). Before CABG, he received subclavian stenting. Although subclavian angiography showed satisfactory results, IVUS imaging revealed mobile plaque protruding through the struts of the stent. An additional stent was deployed in the first stent (stent-in-stenting) to seal it. The patient had no neurological sequelae.

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We investigated long-term outcome of 6 patients with a large or giant aneurysm of the vertebral artery. Patients were 4 men and 2 women, aged from 26 to 74 (mean 56) years old. Only 1 patient presented with subarachnoid hemorrhage, whereas 3 patients presented with signs of brain stem compression and 2 patients with headache. Aneurysms were 18 to 40 (mean 26) mm in maximum diameter and 5 of them were thrombosed in various degrees.
Three patients underwent direct surgery (neck clipping+aneurysmectomy, trapping, coating) and 3 patients were treated conservatively at initial presentation. The latter 3 patients developed deterioration of neurological symptoms and enlargement of the aneurysm within the following 4 to 6 years, and thus 2 patients underwent surgery (neck clipping+aneurysmectomy, endovascular parent artery occlusion). One month after endovascular surgery, however, 1 of the patients died of rupture of aneurysm. Long-term outcome in GOS was as follows: GR (2), SD (1), and D (3). Two patients with GR underwent direct surgery via transcodylar approach at initial presentation for aneurysms less than 30 mm in size.
Although difficult in many cases, neck clipping or trapping with aneurysmectomy via the cranial base approach, before enlarging to “untreatable” size, is the best therapeutic strategy for these aneurysms. On the contrary, long-term outcome of patients with conservative treatment was poor.

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We assessed the therapeutic indications for aneurysmal subarachnoid hemorrhage (SAH) in aged people. Between April 1999 and March 2002, 142 patients with aneurysmal SAH were treated and enrolled in this study. They were divided into 3 groups: 33 patients 75 years old and older (Group A, 23.2%), 37 between 65 and 74 years old (Group B, 26.1%), and 72 64 years old and younger (Group C, 47.4). Hunt and Kosnik grades, Fisher's CT classifications and clinical outcome were evaluated in each group. Clinical outcome was measured by Glasgow Outcome Scale, and good recovery and moderately disabled were defined as favorable outcome. Group A had a significantly higher incidence of serious Hunt and Kosnik grades of patients compared with the other 2 groups (p<0.05, <0.01). Fisher's CT classification was also more severe in Group A than Group C (p<0.05). Therefore the rate of radical treatments was significantly lower in Group A (45.5%) compared with Group B (73.0%) and C (86.1%). Only 4 of the 33 patients (12.1%) with favorable outcome were in Group A, whereas the rates of favorable outcome in Group B and C were 54.1 and 62.5%, respectively. Group A had a significantly poor outcome compared with the other 2 groups. Particularly, none of the patients in Group A with Hunt and Kosnik Grades 4-5 and Fisher's Classification 4 had favorable outcome.
Since there were no significant differences in the rate of radical treatments and clinical outcome between Group B and C, aged people 74 years old and younger should be actively treated in the same manner as the young. In aged people 75 years old and older, however, radical treatment should be restricted to those with Hunt and Kosnik Grade 1-3 and Fisher's CT Classification 2-3.

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Recently less invasive diagnostic tools for the brain have been developed rapidly at a time when the population of the elderly has become enormous. Likewise, the number of patients having uAN-associated ischemic complications has grown sharply. For this special category of uAN, risk-benefit analysis is extremely difficult. Higher morbidity/mortality is common but rupture rates are considered more frequent than incidental uAN.
To prevent bleeding from uAN and to reduce complications triggered by precedent ischemic insult, we have performed radical surgery for such special uAN according to the following guidelines: 1) 70 years old and younger, without serious neurological deficits or general complications, capable of independent life, 2) significant interval (3-6 months) required between precedent ischemic insult and radical surgery, 3) meticulous examination for the etiology of ischemic condition and adequate treatment for the causes, 4) acceptance of prophylactic surgery such as CEA/stent (2 stage), and STA-MCA (concurrent with uAN surgery), 5) prevention of dehydration/hypotension and minimal washout of anti-platelet/thrombotic drug through perioperative period, 6) avoiding too much aspiration of CSF, long-time compression of the brain, temporarily occlusion of arteries, and sacrifice veins. We analyze the results of this series and evaluate the strategy in relation to the cause of complications.
Surgical mortality was 0 and morbidity was observed in 3 patients (permanent: 1; 6.25%, transient: 1; 6.25%). Good results were obtained by our strategy. Precedent ischemic insult may not deeply influence the result. Concurrent bypass did not increase risk of ischemic complication during radical surgery for uAN. However, much attention must be paid to sclerotic perforating artery, brain atrophy, and craniocerebral disproportion in patient with uAN and precedent ischemic accident.

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We studied the bleeding risk during latency period after gamma knife surgery (GKS) for small (3 cm or less) cerebral arteriovenous malformations (AVMs). We analyzed 720 cases with a natural history and 100 cases with GKS. The incidence of bleeding was calculated from the data of the former cases according to the history of bleeding and their age and was compared with the actual number obtained from the latter. The estimated incidence of bleeding was 1.6 for unruptured AVMs and 5.5 for ruptured AVMs, whereas the actual incidence of bleeding was 2 for unruptured and 0 for ruptured. The difference was statistically significant in the ruptured but was not significant in the unruptured.
These results lead us to conclude that the bleeding risk during latency period after GKS for small AVMs is almost the same in the unruptured, but is decreased in the ruptured.

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Few reports have been published on ruptured vertebral artery dissecting aneurysms in which the ipsilateral vertebral arteries distal to the aneurysms are occluded. The proper management of this type of aneurysm is controversial.
We describe 2 patients who presented with subarachnoid hemorrhage and were admitted to our hospital on the day of rupture. CT demonstrated subarachnoid hemorrhage mainly in the posterior fossa. Right vertebral angiography on the day of hemorrhage showed complete occlusion of the right vertebral artery. Left vertebral angiography showed retrograde filling of only the short segment of the distal portion of the right vertebral artery in both patients. Both patients were diagnosed as vertebral artery occlusion after a subarachnoid hemorrhage from a dissecting vertebral artery aneurysm. One patient was treated by trapping. Postoperatively, the patient recovered almost completely with mild hoarseness. The other patient was initially managed conservatively. On the fourth day, however, fulminant rerupture occurred, and 3D-CT angiography showed recanalization of the right vertebral artery. The patient was urgently treated by trapping and recovered well.
The ideal method of treatment for patients with a dissecting vertebral artery with occlusion of the ipsilateral vertebral artery is controversial. Trapping on the day of rupture is one possible treatment option. If conservative management is employed, follow-up neuroimagings such as angiography, 3D-CT angiography and MR angiography within a few days is essential to observe recanalization of the aneurysm.

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